1. Field
The present invention relates to a method of manufacturing semiconductor wafers.
2. Description of the Related Art
In manufacturing semiconductor devices, in order to enable mass production thereof, the diameter of wafers is continuously increased, and even a very large diameter wafer with a diameter of 300 mm or more has emerged. Productivity is enhanced by performing a series of steps in which this large-diameter wafer successively undergoes necessary processes such as polishing, cleaning, drying, CVD, exposure, development and etching, and finally is cut into single pieces. Collectively performing such a series of steps requires a large-scale production facility in the order of hundreds of billions of yen.
However, in recent years, a wide variety of semiconductor apparatuses are also increasingly needed in small quantities for various uses. The above-mentioned large-scale production facility is unsuitable for such limited production of a wide variety of semiconductor apparatuses.
Therefore, recently, a minimal (registered trademark) fab concept has been proposed in which necessary processing treatments are performed on a small wafer with a diameter of about one-half inch (about a size which provides one semiconductor chip). According to this minimal fab concept, a small processing apparatus such as a polishing apparatus, a CVD apparatus is provided for each step so that these processing apparatuses are used in appropriate combination as necessary, thereby making it possible to deal with a wide variety of wafers. As each apparatus may be small, it is possible to suppress the capital-investment spending.
In the above minimal fab concept, it is not contemplated in the foreseeable future to pull up a small-diameter silicon monocrystalline with a diameter of about one-half inch, but rather it is assumed to cut out one-half inch size small-diameter silicon wafers from a current large-diameter silicon wafer.
By the way, also in the past, a patent literature 1 has described cutting out a plurality of small-diameter wafers from a large-diameter semiconductor wafer.